comm.GardnerTimingSynchronizer System object

Description

The GardnerTimingSynchronizer object recovers
the symbol timing phase of the input signal using the Gardner method.
This object implements a non-data-aided feedback method. Gardner timing
synchronization is a non-data-aided feedback method that is independent
of carrier phase recovery. The timing error detector that forms part
of this object's algorithm requires at least two samples per symbol,
one of which is the point at which the decision can be made.

To recover the symbol timing phase of the input signal:

Define and set up your Gardner timing synchronizer
object. See Construction.

Call step to recover
symbol timing phase according to the properties of comm.GardnerTimingSynchronizer.
The behavior of step is specific to each object
in the toolbox.

Construction

H = comm.GardnerTimingSynchronizer creates
a timing phase synchronizer System object™, H.
This object recovers the symbol timing phase of the input signal using
the Gardner method.

H = comm.GardnerTimingSynchronizer(Name,Value) creates
an Gardner timing synchronizer object, H, with
each specified property set to the specified value. You can specify
additional name-value pair arguments in any order as (Name1,Value1,...,NameN,ValueN).

Properties

SamplesPerSymbol

Number of samples representing each symbol

Specify the number of samples that represent each symbol in
the input signal as an integer-valued scalar value greater than 1.
The default is 4.

ErrorUpdateGain

Error update step size

Specify the step size for updating successive timing phase estimates
as a positive real scalar value. The default is 0.05.
Typically, this number is less than 1/SamplesPerSymbol,
which corresponds to a slowly varying timing phase. This property
is tunable.

ResetInputPort

Enable synchronization reset input

Set this property to true to enable resetting
the timing phase recovery process based on an input argument value.
The default is false. When you set this property
to true, you must specify a reset input value to
the step method. When you specify a nonzero value
as the reset input, the object restarts the timing phase recovery
process. When you set this property to false, the
object does not restart.

ResetCondition

Condition for timing phase recovery reset

Specify the conditions to reset the timing phase recovery process
as one of Never | Every frame.
The default is Never. When you set this property
to Never, the phase recovery process never restarts.
The object operates continuously, retaining information from one symbol
to the next. When you set this property to Every frame,
the timing phase recovery restarts at the start of each frame of data.
In this case, the restart occurs each time the object calls the step
method. This property applies when you set the ResetInputPort property
to false.